ZBTB20 promotes malignancy and stemness in lung squamous cell carcinoma through the transcriptional repression of KCTD1 and activation of Hedgehog signaling

Abstract

Prostate Potassium channel tetramerization domain containing 1 (KCTD1) is a tumor suppressor that inhibits the Hedgehog (Hh) signaling pathway. The aim of this study was to investigate the role of KCTD1 in lung squamous cell carcinoma (LUSC) and its impact on the Hedgehog (Hh) pathway. Jervine, a known Hh signaling inhibitor, was used to validate the function KCDT1. After ascertaining the expression pattern of KCTD1 in LUSC tissues, gain- and loss-of-function experiments were conducted to analyze the impact of KCTD1 on the malignant behavior and stemness of LUSC cells malignancy, and the activation of Hh pathway. Tumor allografts were established in mice for in vivo validation. Zinc finger and BTB domain-containing 20 (ZBTB20) was identified as a potential upstream regulator of KCDT1 through bioinformatics approaches. To determine the role of ZBTB20 in LUSC progression, the cell lines were transfected with the expression construct, and Jervine was used for functional rescue experiments. Although KCTD1 was upregulated in LUSC, its expression predicted a favorable prognosis. KCTD1 knockdown reduced the proliferation, migration, clonogenic potential, and stemness of LUSC cells by activating the Hh pathway, while Jervine treatment reversed these oncogenic effects. Furthermore, ZBTB20 was downregulated in the LUSC tissues, and its overexpression downregulated KCTD1 through transcriptional repression, and activated the Hh pathway, thereby enhancing the malignant behavior of LUSC cells. However, these oncogenic effects were counteracted by either Jervine treatment, or by restoring KCTD1 expression. Overall, this study shows that KCTD1 reduces malignancy and stemness in LUSC cells by inactivating the Hh signaling pathway.